Radar antenna driving mechanism



Aug. 23, 1949, BAXTER ETAL 2,47%,897

RADAR ANTENNA DRI ING MECHANISM Filed April 17, 1947 v 4 Sheets-Sheet 1 HABAXTER 11.7". BUDENBOM 2? %ac% mail ATTORNEY IN [/5 N T 0798 1949 H. A. BAXTER ETAL 2,479,897

RADAR ANTENNA DRIVING MECHANISM Filed April 1'7, 1947- 4 Sheets-Sheet 2 I HA .BAXTER MEMO 'H 7TBUDNBOM A TTORNE) Aug. 23, 1949. H. A. BAXTER ET AL RADAR ANTENNA DRIVING MECHANISM 4 Sheets-Shec 5 Filed .April 17, 1947 iii-5L.

mil llm'r I 1111111; 717111114 III"! HABAXTER WKNTORS 'HFBUOENBOM 19 -%Q %VKM ATTORNEY 31949 H. A. BAXTEF Q ETAL RADAR ANTENNA DRIVING" MECHANISM 4 Sheets-Sheet 4 Filed April 17', 1947 Patented Aug. 23, 1949 RADAR ANTENNA DRIVING MECHANISM Howard A. Baxter, Green Village, and Horace T. Budenbom, Short Hills, N. J., assignors to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application April 17, 1947', Serial No. 742,090

1 Claim.

This invention relates to radio signaling apparatus and more specifically to a scanning mechanism for use in such apparatus.

The object of the present invention is the provision of a scanning mechanism of the type above referred to which will be simple in construction, and positive in operation.

In the drawing:

Fig. 1 is a side elevation view shown with a number of operating parts in section and the reflector in normal position;

Fig. 2 is a rear elevation view shown with the wave guide and a number of operating parts with portions broken away;

Fig. 3 is a top view shown with the wave reflector in operated position and a number of operating parts partly in section;

Fig. 4 is an enlarged view of a gear and clutch operating mechanism used in the scanning mech anism of the invention, the casing being shown in horizontal section taken on line 44 of Fig. 3; and

Figs. 53, 5C, 5D, 5F and 5E are diagrammatic views of scanning fields obtained by the scanning mechanism of this invention.

According to this invention, a base in the form of a casting i is formed with an upright extending sleeve portion H, in which is secured as by set screws, a hollow spindle I2 serving for pivotally mounting a circular turntable [4 having a V-shaped groove at its periphery for receiving a belt 21 of trapezoidal cross-section. The turntable I4 is formed with a circular rim portion l best seen in Figs. 1 and 2 serving for mounting a plurality of equally spaced radially disposed studs i5 held securely on the rim portion by nuts I1 and on these studs are mounted the rollers l8 bearing against the sides of a horizontally disposed flat ring IS, the ring l9 forming a race track for the turntable I4 supported by a circular ridge 2!! formed with the base Ill.

The base Ill is provided with a machined surface on which is secured an angle-shaped bracket 2| formed with two parallelly-disposed arms 22 and 23 serving for rotatably supporting a shaft 24 on which is keyed a pulley 25 and a worm gear 26. The pulley 25 is operatively con nected to the turntable M by the belt 2'! while the worm gear 26 is operatively connected to a worm 28 keyed on the armature shaft of a motor 29 secured to the angular-shaped bracket 2| by a plurality of bolts 30. On turntable I4 is secured as by a number of bolts 31 two upwardly extending arms 32 and 33 formed at their free ends with bearing portions 34 and 35, r-espective- 2 1y provided for rotatably supporting the pivots 36 and 31 formed with a casing 38, the latter serving for housing a combined gear and clutch mechanism which will be hereinafter described in detail. 5

Casing 38 is provided with downward extending projections 39 best seen in Figs. 1 and 2 serving for securing as by a number of screws 40a: a motor 40 to the armature shaft of which is keyed a. V-grooved pulley 4i operatively connected to a similar pulley 42 by a belt 43 of trapezoidal cross-section best seen in Figs. 1 and 4. Pulley 42 is keyed. on one end of a hollow shaft or sleeve 44, the opposite end of which is keyed to the hub portion 46 of a cylindrical casing by a key member 41y. Casing 45 is rotatably mounted on ball bearings 41 and 48. Bearing 48 is fitted into a counterbore in a cover member 49 secured to the front end of casing 38 by a number of screws 50, while bearing 41 is fitted into a counterbore in the hub portion 5| of casing 38, and is held in place therein by a fiat ring 52 secured to hub 5| of casing 38 by a plurality of screws 53, a screw-threaded ring 54 bein provided for holding the inner ring of bearing 4'! securely on the hub 46 of casing 45, best seen in Fig. 4.

On the hub portion of a cover 55m secured to the front end of casing t5 there is secured as by a plurality of bolts 56, a yoke-shaped member 51 of U-shaped cross-section to the ends of which are secured as by a plurality of bolts 58,. similar angularly-shaped pieces 59 best seen in Figs. 1 and 2. These angular pieces are each provided with a pivot 60 for. receiving bearings as Bl. secured to a tubular frame 62 by respective clamping devices in the form of plates 63 and 64 and screw 65.

The tubular frame 62 is provided with a ring of circular tubing 56 to which is secured as by a plurality of bolts (not shown) a parabolic reflector 61. The tubular frame 62 and the reflector 61 carried thereby may be moved as a unit on the. pivots 60 from the position shown in Figs. 1 and 2 to the positions shown in Fig. 3 by a mechanism comprising a SOcKSt member 68 car ried by a plate 69 which is secured on the. tubular frame 62 by a plurality of bolts l0 and a cylindrically shaped piece H fitted into the socket 68 in the manner of a so-called knuckle joint, the cylindrical piece H having a drilled hole engaged by a crank pin '52 extending perpendicularly from a disc member 13 keyed on one end of a shaft 14 best seen in Fig. 4 journaled in bearings BI and B2 fitted in the hub 55 of cover 553: for casing 45. According to this construction the rotation of casing 45 is effective to rotate the tubular frame 62 and the reflector 61 carried thereby in position perpendicular to the longitudinal axis of casing 45, while the rotation of shaft 14 and the crank mechanism formed by disc 73 and crank pin 12 is effective to impart a swinging movement to the tubular frame and to the reflector from the position shown in Figs. 1 and 2 to the positions shown in Fig. 3.

The operation of crank pin 12 in addition to imparting a swinging movement to the reflector 6'1 is effective to impart a linear reciprocating movement to a longitudinally movable bar 15 having gear rack portions Y as best seen in Fig. 3 for actuating potentiometer devices 76 and T! connected in the electrical circuit of the radio signaling device (not shown) and which forms no part of the present invention.

The shaft 74 is actuated in conjunction with casing 45 by a combined gear and friction clutch mechanism best seen in Fig. 4 comprising the hollow shaft 44 keyed to the casing 45 and a shaft 18 slidably mounted in hollow shaft 44 but held against rotation therein by a pin 19 best seen in Fig. 1, extending diametrically through the shaft and through prongs formed at one end of a double armed lever 89, pivoted as at 8! on a bracket 82 secured on casing 39 as by a plurality of screws 83. The opposite end of lever 89 is operatively connected to one end of a plunger 84 of a solenoid 85 secured on bracket 82 by a number of screws 86. The shaft is is formed with a screw-threaded reduced portion for mounting a ball bearing B3 and carries a pinion 81 serving to cause the rotation of a gear 88 and that of a pinion 89 keyed on a shaft 99 upon the rotation of casing 45 and therefore the planetary movement of gear 88 and pinion 91.

The shaft 99 is journaled in bearings 9i and 92 carried by casing 45. Pinion 89 meshes with a gear 93 formed with a pinion 94 mounted for free rotation as a unit on the reduced end portion of shaft 18, while the pinion 94 meshes with a gear 95 keyed on a shaft 96 for rotating the latter and a pinion 9! formed with the shaft 96, this shaft being journaled in bearings 98 and 99 vfitted in counterbore holes in casing 45 and its cover element 55x. Pinion 9! meshes with a gear I99 mounted for free rotation on the reduced end .portion of shaft 18 and carries a friction clutch element lfll disposed for engaging a cooperating clutch element I92 carried by a disc portion I93 formed at one end of a sleeve H14 mounted for sliding movement on the shaft 14 but held against rotary movement thereon by a pin I95 diametrically extending from shaft 14, the clutch elements llJl and I92 being normally held in frictional engagement against each other by a spring I96 having one of its ends abutting against a collar I91 formed with the shaft 74 and its other end against a disc portion HIS formed with sleeve I94. thus holding the slidable shaft 18 and the plunger 84 of the solenoid 85 in the retracted position through the ball bearing B3. which also serves for holding the reduced end of shaft 18 in coaxial alignment with the sleeve I94.

To the disc portion I98 is secured a friction clutch element N19 for enga ement with a friction clutch element H9 secured on the hub portion 55 of cover 55:12, for operativelv connecting the shaft T4 with the casing 45 which. as above mentioned is rotated by pulley 42. the gear reduction mechanism for operating the shaft 74 when the clutch elements I99 and I ID are engaged being 4 of the order of 625 turns of hollow shaft 44 for each turn of shaft 14.

On the upward extending arm 32, as best seen in Figs. 1 and 2 is secured as by a number of screws HOY, an angle-shaped bracket Ill serving for mounting a motor H2. On the armature shaft of this motor is keyed a worm I I3 meshing with a worm gear H4, keyed at one end of a spindle I I5 mounted for free rotation in a bushing portion H6; formed with arm 32 and on spindle H5 is keyed a pinion H1 engaging a gear sector H8 keyed on the spindle 36 for imparting vertical reciprocating rotary movement to the gear assembly thus formed and to the reflector 6! carried thereby independently of or in cooperation with the operation of motors 29 and 40 to cause the reflector to generate scanning fields as shown in Figs. 53 to 5F, inclusive, in a manner which will be hereinafter described in detail.

In a typical example of operation of the scanning mechanism of this invention, considering the reflector 61 in position as shown in Figs. 1 and 2, i. e., perpendicular to the longitudinal axis of casing 45, the operation of motor 29 is effective to rotate the turntable l4 and thereby moving the reflector 6'! in an azimuth direction as shown diagrammatically in Fig. 5D which may be continued in either clockwise or counterclockwise direction or reciprocally by alternatively reversing the operation of motor 29.

The operation of motor H2 independently of the operation of motor 29 in a clockwise and counter-clockwise direction is effective through the Worm gear H3, worm H4, pinion H1 and gear sector H8 keyed on spindle 36 to impart vertical reciprocating movements to the reflector 6! as shown diagrammatically in Fig. 5C whereas the combined clockwise and counter-clockwise operation of motors 29 and I I2 in timed relation to each other is effective to actuate the reflector 61 in a manner to generate a scanning field representing a zigzag as shown in Fig. SF.

The independent operation of motor 40 is effective to rotate the pulley 42 keyed on hollow shaft 44 and thereby the casing 45 relative to its supporting casing 38. The rotation of casing 45 and thereby the planetary movement of gear 88 meshing with stationary pinion 8! is effective through the pinion 89, the gear 93, the pinion 94, the gear 95 and pinion 9'! to rotate the gear I99 at a reduced speed relative to that of casing 45 and thereby of the shaft 14 through the pin "15 and the clutch elements I Ill and H92 now held in engagement by the normal tension of spring H16. The rotation of casing 45 is effective to rotate reflector 6'! in position perpendicular to the longitudinal axis of casing 45, while the rotation of shaft 14 simultaneously with the rotation of casing 45 as above described is effective to impart oscillatory movements to the reflector as effected by the crank pin 12, such combined movements causing the reflector to generate a scanning field representing a spiral as shown in Fig. 5B.

The operation of the clutching mechanism, as effected by the longitudinal movement of shaft 18 under control of the solenoid is effective through the end thrust bearing- B3 to disengage the clutch elements IUI and I92 and engage the clutch elements I99 and H0 for connecting the shaft 14 direct with the casing 45. thereby renderin-g the crank mechanism ineffective to impart oscillatory movements to the reflector during the rotation of casing 45, thus causing the refiector to generate a scanning field representing a cone as shown in Fig. 5E which may have any angle within the capacity of the crank mechanism. The wave guide consists of the feed horn M0 connected to the tubular member Ml. This tubular member is formed with a ring-shaped portion I42 cooperating with a. ring portion M3 at one end of a tubing M4 to form a so-called rotary joint, While the opposite end of tubing I44 terminates in the form of a cylindrical portion 145 to form in cooperation with a cylindrical portion MS a rotary joint at the center of the turntable, this joint connecting with a tubing l4! leading to the electrical apparatus not shown and which form no part of the present invention.

What is claimed is:

In a radio signaling apparatus, a wave reflector, a base, a moLmt-ing table rotatably supported on said base, a motor to rotate said mounting table, a pair of arms carried by said table, a first casing pivoted on said arms, a motor operable to tilt said first casing, a second casin supported in said first casing and operable to rotate in said first casing, a yoke secured to said second casing, a frame pivotally supported in said yoke and supporting said reflector, a motor to rotate said second casing, a rotatable shaft supported in and extending from said second casing, a crank on said rotatable shaft and extending into mechanical connection with said frame, a gear mechanism in said second casing, a clutch device between said second casing and said rotatable shaft and between said gear mechanism and said rotatable shaft, said clutch device being operable in one position to clutch connect said second casing to said rotatable shaft and being operable in another position to clutch connect said gear mechanism to said rotatable shaft, said second casing when clutch connected to said rotatable shaft being operable to cause said crank to rotate at the same speed as that of said second casing, said gear mechanism when clutch connected to said rotatable shaft being operable to cause said rotatable shaft and said crank to rotate at a speed different from the speed of rotation of said second casing and reflector and operating to cause said frame and said reflector to move in an oscillatory manner at a speed different from that of said second casing, and an electromagnetic device to control the position of said clutch device relative to said second casing and said gear mechanism, said wave reflector being operable to reflect a wave in a circular pattern when said clutch device connects said second casing to said rotatable shaft, and beingoperable to reflect a wave in a spiral pattern when said clutch device connects said gear mechanism to said rotatable shaft.

HOWARD A. BAXTER. HORACE T. BUDENBOM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,410,831 Maybarduk et a1. Nov. 12, 1946 2,412,612 Godet Dec. 17, 1946 2,412,867 Briggs et a1 Dec. 17, 1946 2,415,678 Edwards Feb. 11, 1947 2,437,275 Skene et al. Mar. 9, 1948 

